CATIE News

26 March 2015 

Age-related macular degeneration in HIV

In our previous CATIE News story, we provided some general information about age-related macular degeneration (AMD). In this CATIE News bulletin, we focus on reports of AMD in HIV-positive people.

Researchers at Mt. Sinai Hospital in New York City and elsewhere in the U.S. have been monitoring the eyes of people who have survived AIDS. They found that out of 1,825 participants, 10% had intermediate-stage AMD. Compared to HIV-negative people, the rate of AMD among these long-term survivors of AIDS was four-fold greater. The findings and implications of this study are discussed below.

Study details

Researchers across 19 cities in the U.S. recruited participants for a study of eye health. Recruitment started in 1998 and ended in 2011. All participants had been diagnosed with AIDS, some with eye-related complications. As part of the study, photographs of the retina of each person’s eye were taken and assessed. For the present analysis focusing on AMD, researchers did not use data from people who had AIDS-related complications of the eyes.

The average profile of participants upon entering the study was as follows:

  • 81% men, 19% women
  • age – 43 years
  • CD4+ count – 198 cells/mm3
  • lowest-ever CD4+ count – 44 cells/mm3
  • viral load – 500 copies/ml
  • highest-ever viral load – 20,000 copies/ml

Results

Almost 10% of participants had intermediate-stage AMD. People with this diagnosis can develop visual difficulties—in some cases, severe—over time.

Potential risk factors

Researchers analysed many potential factors that participants had at the time they entered the study and found that the following were statistically linked to an increased risk for AMD:

  • age – for every decade above the age of 29 years, participants had a two-fold increased risk for developing AMD
  • HIV risk category – people who injected street drugs or who self-identified as heterosexual had about a two-fold increased risk for developing AMD compared to gay or bisexual men

Comparisons

Researchers compared rates of AMD from data collected from HIV-negative people from a study of several thousand residents of the city of Beaver Dam in Wisconsin (the so-called Beaver Dam study). In that study, participants also underwent extensive eye examinations. In their comparison, the researchers found that HIV-positive people in the present study were four times more likely to develop AMD than HIV-negative people.

Bear in mind

The present analysis of AMD in HIV-positive people is cross-sectional. That is, data from one point in time were assessed. Therefore, drawing conclusions about possible cause(s) of AMD from such a study design needs to be done extremely cautiously. The potential causes of AMD named in the present study are interesting and seem to make intuitive sense. For instance, age is a well-known risk factor for AMD and the researchers stated that, in their experience, people who inject street drugs are at increased risk for AMD.

Readers should be aware that even if the findings from the present study are accurate, they are unlikely to apply to all HIV-positive people. This is because many participants had very low CD4+ counts in the past (less than 50 cells/mm3), which would suggest that they had serious immunological issues at some point. Such low CD4+ counts could have predisposed participants to increased inflammation and other immune-related problems, in turn increasing their risk for AMD.

Over the past several years, in high-income countries, clinical practice and treatment guidelines have been encouraging the early initiation of potent combination anti-HIV therapy (commonly called ART or HAART), so having such low CD4+ counts (and the attendant immunological injury) is less likely these days. Thus the study’s findings may not apply to people whose CD4+ counts had never fallen to such low levels.

The reasons for the increased risk of AMD among this group of HIV-positive people are not certain. But the Mt. Sinai researchers suspect that factors such as excessive immune activation and inflammation before participants received ART may have played a role.

Other clinics should consider whether or not to confirm the findings from the U.S. study. At a minimum, the study’s findings point to the need for HIV-positive people to have regular and comprehensive eye examinations so that doctors can catch cases of AMD (and any other eye complications) early and, when possible, prescribe treatments to stabilize this condition.

Resources

Management of Human Immunodeficiency Virus Infection in Advanced Age

Long-term HIV infection and health-related quality of lifeCATIE News

Dutch doctors explore intersection of aging and HIVCATIE News

Report to the NIH about Aging and HIV

The CIHR Comorbidity Agenda

CIHR’s HIV Comorbidity Research Agenda: Relevant Research Areas

HIV and Aging – Healthy living tips for people 50 and over living with HIV

HIV and Aging – CATIE Webinar Series: Building Blocks

Factsheets on HIV and aging in Canada – Canadian AIDS Society

Evidence-informed recommendations for rehabilitation with older adults living with HIV: a knowledge synthesis

—Sean R. Hosein

REFERENCE:

Jabs DA, Van Natta ML, et al. Prevalence of intermediate-stage age-related macular degeneration in patients with the acquired immunodeficiency syndrome. American Journal of Ophthalmology. 2015; in press.